Securing cargo

ABSTRACT

A buckle  10  for use in securing cargo by means of a flexible cargo strap has at least one surface  16  against which the strap bears, in use. The surface  16  is abrasive, in one example. This is achieved by coating the surface in a grit material  18.

The present invention relates to methods and apparatus for securingcargo.

Many situations arise in which there is a requirement to secure cargo bymeans of straps. In some circumstances, metal straps may be used undertension, with a seal device to hold the ends of the strap together.Metal straps have the disadvantage that when cut under tension, the cutends may whip away from the cargo, as the tension is released,presenting a danger to personnel.

In an alternative, extruded or woven straps such as polyester or anothersynthetic plastic material are used with buckles. These straps have areduced tendency to whip when cut under tension, and are less dangerousif they do, but it is found that the tension which can be achieved withknown plastic strap and buckle arrangements is less than with knownmetal strap arrangements, resulting in a less secure hold on the cargo.

Examples of the present invention provide a buckle for a flexible cargostrap, comprising:

-   -   at least one surface against which the strap bears, in use, and        wherein the surface is coated in a grit material.

The coated surface may have an adhesive coating by which the gritmaterial is secured to the coated surface. The adhesive coating may be awater-based adhesive. Alternatively, the coated surface may be coated byan abrasive coating containing grit material.

The grit material may be an abrasive grit. The grit material may betungsten carbide, diamond, crushed glass, sand, silica powder, aluminiumoxide, pumice or iron oxide.

The coated surface may be provided by the surface of a length of metalrod. The metal rod may be bent to form the buckle. The metal rod may besteel.

The buckle may comprise:

-   -   a first surface around which a working end of the strap is        wrapped, in use, and    -   a second surface against which the working end is pressed, in        use, by tension in the bight of the strap,    -   one or both of the first and second surfaces being coated in        grit material, as aforesaid.

The buckle may further comprise a third surface corresponding with thefirst surface, for the other working end of the strap, and a fourthsurface corresponding with the second surface, against which the otherworking end is pressed, in use, and wherein one or both of the third andfourth surfaces are coated in grit material, as aforesaid.

Examples of the present invention also provide a cargo strappingarrangement comprising a flexible cargo strap for passing around thecargo, and a buckle as defined in any of the preceding definitions, forsecuring the ends of the cargo strap together.

Examples of the present invention also provide a cargo strappingarrangement comprising a flexible cargo strap around a cargo, and abuckle as defined in any of the preceding definitions, the bucklesecuring the ends of the cargo strap together.

The strap may be woven or extruded and may be a synthetic plasticmaterial.

Examples of the present invention also provide a buckle for a flexiblecargo strap, comprising at least one abrasive surface against which thestrap bears, in use.

Examples of the present invention will now be described in more detail,by way of example only, and with reference to the accompanying drawings,in which:

FIG. 1 is a simplified perspective view of a cargo secured by a strapand buckle arrangement of one example of the present invention;

FIG. 2 shows the part of FIG. 1 labelled “2”, on an enlarged scale;

FIGS. 3, 4 and 5 are perspective, plan and side views, respectively, ofthe buckle shown in use in FIGS. 1 and 2, FIG. 3 being on an enlargedscale; and

FIG. 6 is a side view of the buckle, in use with a strap.

The drawings illustrate a buckle 10 being used to secure a cargo 12 bymeans of a flexible cargo strap 14 which extends around the cargo 12. Aswill be described in more detail below, the buckle 10 has at least onesurface 16 (FIG. 3) against which the strap 14 bears, in use. Thesurface 16 is abrasive, in this example. The surface 16 is coated in agrit material 18, in this example.

In more detail, the cargo 12 illustrated in FIG. 1 is a bundle ofelongate items. The cargo strap 14 extends around the cargo 12. Thebight 20 of the strap 14 is held in position around the cargo 12 bysecuring together the free or working ends 22 of the strap 14 by meansof the buckle 10. This can be seen particularly in FIGS. 2 and 6. Theworking ends 22 follow a convoluted path around elements of the buckle10 to create friction between the working ends 22 and the buckle 10.This friction serves to hold the bight 20 under tension.

In the example being described, both ends of the strap 14 are used asworking ends 22 for engagement with the buckle 10 in similar manner.Alternatively, one end may be secured permanently to the buckle 10,leaving only a single working end 12 for threading through the buckle10, after the bight 20 has been passed around the cargo 12.

The buckle 10 is formed from a length of rod or bar bent into a loop ofgenerally square or rectangular form. The material of the buckle 10 maybe a steel, such as bright drawn mild steel. The buckle 10 has twoterminal arms 24 which extend generally parallel to each other, to theextreme ends 26. The terminal arms 24 therefore define a plane 25,indicated in FIG. 5. Between the terminal arms 24, the buckle is bent toform a generally square or rectangular loop 28 in a second plane 29. Theends of the loop 28 are connected with the terminal arms 24 by slopingportions 30. The plane of the terminal arms 24 is spaced slightly fromthe plane of the loop 28. The loop 28 has two generally straight sideportions 32 running generally parallel with, and slightly spaced fromrespective terminal arms 24.

Grit material 18 is coated onto various surfaces of the buckle 10, ashas been described. In this example, grit material 18 is coated onto theterminal arms 24. Grit material 18 is also coated onto the side portions32. In each case, grit material 18 is preferably coated aroundsubstantially the whole circumference of the arm 24 or portion 32, andalong substantially the whole length of the arm 24 or portion 32.

In this example, the coated surfaces have an adhesive coating by whichthe grit material is secured to the coated surface. In this example, theadhesive coating is a water-based adhesive. Other adhesive materials maybe used. The grit material may be an abrasive grit. The grit materialmay be tungsten carbide, diamond, crushed glass, sand, silica powder,aluminium oxide, pumice or iron oxide. An abrasive coating containinggrit material may be applied to the surface to be rendered abrasive, forexample by applying a paint into which the grit has been introduced.

When the strapping arrangement is used, each working end 22 of the strap14 is threaded through the buckle 10 in the manner which is illustratedin FIGS. 2 and 6. After passing the bight 20 around the cargo 12, theworking end 22 is passed between the buckle 10 and the cargo 12. Thebuckle 10 is positioned with the loop 28 facing the cargo 12, betweenthe cargo 12 and the terminal arms 24. The working end 22 is then passedthrough the loop 28, between the terminal arms 24, around one of theterminal arms 24 and back through the loop 28. The working end 22 thenpasses away from the buckle 10, under the respective side portion 32.Both ends of the strap 14 may be threaded in this manner, as illustratedin FIGS. 2 and 6, or one end of the strap 14 may be threaded, the otherbeing permanently attached to the buckle 10, as noted above.

Once threaded in this manner, the working end 22 can be pulled throughthe buckle 10 to increase the tension in the bight 20. A tensioning toolmay be used for this purpose. As the bight tension increases, the bight20 becomes pressed more tightly toward the side portion 32. This trapsthe working end 22 between the side portion 32 and the bight 20. Thetension in the bight 20 also serves to pull the working end 22 againstthe terminal arm 24.

This results in friction between the working end 22 and the surface ofthe terminal arm 24, and further friction between the working end 22 andthe side portion 32. In particular, friction will be created between theworking end 22 and those regions of the terminal arms 24 which face awayfrom the cargo 12. Further friction will be created particularly betweenthe working end 22 and the surface of the side portion 32, particularlythose regions of the side portion surface which face the cargo 12 andface inwardly of the loop 28.

It is one or more of these regions, in particular, which are coated withthe grit material 18. Accordingly, this friction is enhanced by theabrasive nature of the grit material 18. We have found grit material tobe compatible with extruded or woven cargo straps, particularly thosemade of synthetic plastics materials such as polyester, because of thetendency of the grit material to dig into the polyester. This createsgood grip of the strap by the buckle, even if the strap is wet.

Tension in the bight 20 can be further increased by pulling additionallengths of the working ends 22 through the buckle 10.

In one example, the buckle 10 is manufactured by first bending asuitable length of buckle material to the required form and then dippingthe buckle 10 into adhesive. After coating the buckle 10 with adhesive,it may be dipped into grit material 18, preferably in powder or granularform, to coat the buckle 10. This dipping process can readily coat theentire surface of the buckle 10 with adhesive, and therefore with gritmaterial. We have found that this may further assist the retention ofthe strap 14. For example, the edges of the strap 14 may rub against thesloping portions 30, so that grit material 18 on the sloping portions 30can provide a further contribution to the performance of the buckle 10.Similarly, the sloping portions 30 may rub against each other if thebuckle 10 deforms under load and again, the presence of grit material 18on the sloping portions 30 may further contribute to the performance ofthe buckle 10.

Alternatively, grit material 18 may be applied selectively to regions ofthe surface of the buckle 10, particularly those regions noted above ascontributing to the grip of the working end 22 by the buckle 10.

Many variations modifications can be made to the apparatus describedabove, without departing from the scope of the invention. In particular,the shape, form, dimensions and relative dimensions of the buckle may bechanged, for example to modify the grip characteristics and toaccommodate different sizes of strap 14. Many different grit materialscould be used in addition to those described. The grit material may bechosen, in part, with reference to the form and material of the strapwith which the buckle is intended to be used. The adhesive material maybe chosen, in a practical situation, to be compatible with the materialof the buckle 10 and of the grit material 18.

Whilst endeavoring in the foregoing specification to draw attention tothose features of the invention believed to be of particular importanceit should be understood that the Applicant claims protection in respectof any patentable feature or combination of features hereinbeforereferred to and/or shown in the drawings whether or not particularemphasis has been placed thereon.

1. A buckle for a flexible cargo strap, comprising: at least one surfaceagainst which the strap bears, in use, and wherein the surface is coatedin a grit material.
 2. A buckle according to claim 1, wherein the coatedsurface has an adhesive coating by which the grit material is secured tothe coated surface.
 3. A buckle according to claim 2, wherein theadhesive coating is a water-based adhesive.
 4. A buckle according toclaim 1, wherein the coated surface is coated by an abrasive coatingcontaining grit material.
 5. A buckle according to claim 1, wherein thegrit material is an abrasive grit.
 6. A buckle according to claim 1,wherein the grit material is tungsten carbide, diamond, crushed glass,sand, silica powder, aluminum oxide, pumice or iron oxide.
 7. A buckleaccording to claim 1, wherein the coated surface is provided by thesurface of a length of metal rod.
 8. A buckle according to claim 7,wherein the metal rod is bent to form the buckle.
 9. A buckle accordingto claim 7, wherein the metal rod is steel.
 10. A buckle as claimed inclaim 1, further comprising: a first surface around which a working endof the strap is wrapped, in use, and, a second surface against which theworking end is pressed, in use, by tension in the bight of the strap,one or both of the first and second surfaces being coated in gritmaterial, as aforesaid.
 11. A buckle according to claim 10, wherein thebuckle further comprises a third surface corresponding with the firstsurface, for the other working end of the strap, and a fourth surfacecorresponding with the second surface, against which the other workingend is pressed, in use, and wherein one or both of the third and fourthsurfaces are coated in grit material, as aforesaid.
 12. A cargostrapping arrangement, comprising: a flexible cargo strap for passingaround the cargo, and a buckle as claimed in claim 1, for securing theends of the cargo strap together.
 13. (canceled)
 14. A cargo strappingarrangement according to claim 12, wherein the strap is woven.
 15. Acargo strapping arrangement according to claim 12, wherein the strap isextruded.
 16. A cargo strapping arrangement according claim 12, whereinthe strap is a synthetic plastic material.
 17. A buckle for a flexiblecargo strap, comprising: at least one abrasive surface against which thestrap bears, in use.
 18. A buckle according to claim 17, furthercomprising: a first surface around which a working end of the strap iswrapped, in use, and, a second surface against which the working end ispressed, in use, by tension in the bight of the strap, one or both ofthe first and second surfaces being abrasive, as aforesaid.
 19. A buckleaccording to claim 18, wherein the buckle further comprises a thirdsurface corresponding with the first surface, for the other working endof the strap, and a fourth surface corresponding with the secondsurface, against which the other working end is pressed, in use, andwherein one or both of the third and fourth surfaces are abrasive, asaforesaid.
 20. (canceled)
 21. (canceled)
 22. (canceled)